GDD update 6.25.19

Getting close to breaking the 1000 mark in some areas (sorry Canton and Williamson) and this week may be the first week of all 80’s in Ithaca so far.


What’s in a name? We all get used to using common names but sometimes they are confusing.  Bagworms and tent caterpillars aren’t the same thing although they do both make habitats for themselves.  And sometime the management is different. Even within a group telling them apart is hard.  Here’s a comparison of tent caterpillars and Gypsy moth larvae:


I don’t think of tent caterpillars as Christmas tree pests.  Ever seen them on your trees?  Bagworm could be but I hear more about that in landscapes.  Gypsy moth?  Yes! I think that’s what ‘those little black worms’ the caller was asking about probably are.


In case you have them – bagworm larvae emerge from their bags at 650-750 GDD. And Gypsy moths are getting ready to pupate in some areas (around 450 GDD) – so no more management methods will work.


I learned many things from Rich Cowles at the Dutchess County Twilight (nice to see some of you there, too).  Scale crawlers that stay under the female covering are hard to smother with dormant oil because there is an air space for them.  Makes sense (and I am an insect geek!).


Keeping weeds down makes it easier to scout for elongate hemlock scale as they start on the lower inner branches and move up.


Continue scouting for these:


Two spotted spider mite – 363-618 GDD

Cryptomeria scale crawlers – 600-800 GDD

Elongate hemlock scale crawlers – 360-700 GDD

Gypsy moth larvae – 90-448 GDD

Douglas fir needle midge adults –  200-400 GDD

Pine needle scale crawlers – 298-448

Striped pine needle scale crawlers – 400-500

Introduced and red-headed pine sawfly larvae – 400-600